diff --git a/packages/mermaid/src/config.ts b/packages/mermaid/src/config.ts
index 8750c8fa5..bc0066cec 100644
--- a/packages/mermaid/src/config.ts
+++ b/packages/mermaid/src/config.ts
@@ -243,6 +243,7 @@ const checkConfig = (config: MermaidConfig) => {
   if (!config) {
     return;
   }
+  // @ts-expect-error Properties were removed in v10. Warning should exist.
   if (config.lazyLoadedDiagrams || config.loadExternalDiagramsAtStartup) {
     issueWarning('LAZY_LOAD_DEPRECATED');
   }
diff --git a/packages/mermaid/src/config.type.ts b/packages/mermaid/src/config.type.ts
index 474075824..c835ee440 100644
--- a/packages/mermaid/src/config.type.ts
+++ b/packages/mermaid/src/config.type.ts
@@ -3,10 +3,6 @@
 import DOMPurify from 'dompurify';
 
 export interface MermaidConfig {
-  /** @deprecated use mermaid.registerLazyDiagrams instead */
-  lazyLoadedDiagrams?: string[];
-  /** @deprecated use mermaid.registerLazyDiagrams instead */
-  loadExternalDiagramsAtStartup?: boolean;
   theme?: string;
   themeVariables?: any;
   themeCSS?: string;